Fiber optic connectors of a wide variety of designs have been employed to terminate optical fiber cables and to facilitate connection of the cables to other cables or other optical fiber transmission devices. A typical optic fiber connector includes a ferrule which mounts and centers an optical fiber or fibers within the connector. The ferrule may be fabricated of such material as ceramic. A ferrule holder or other housing component of the connector embraces the ferrule and may be fabricated of such material as molded plastic. A spring may be disposed within the housing or ferrule holder such that the ferrule is yieldably biased forwardly for engaging another fiber-mounting ferrule of a mating connecting device.
A pair of fiber optic connectors or a connector and another optical fiber transmission device often are mated in an adapter which centers the fibers to provide low insertion losses. The adapter couples the connectors together so that their encapsulated fibers connect end-to-end. The adapter may be an in-line component, or the adapter can be designed for mounting in an opening in a panel, backplane, circuit board or the like.
Various problems are encountered when terminating optical fibers in fiber optic connectors versus terminating electrical conductors in electrical connectors, when situations arise wherein a fiber end of an "active" fiber optic connector is exposed. A typical situation might arise when one of the fiber optic connectors at one end of an adapter is removed, leaving the other "active" fiber optic connector in the adapter.
In particular, an exposed fiber end may be damaged by adverse environmental hazards, and the accumulation of dust and dirt may impair the optical transmission capabilities of the fiber. Another very important problem is to protect an operator's eyes from dangerous light beams from the exposed end of an active optical fiber. For instance, an operator's eyes may be damaged from dangerous light beams exiting an unprotected receptacle or adapter.
Heretofore, dust covers, end caps or spring-loaded shutters have been used to close an open end of an adapter to, thereby, cover the exposed fiber ends to protect the fiber ends from adverse environmental hazards and to prevent light energy from the fiber ends from exiting the adapter. One such spring-loaded shutter is pivotally mounted on the adapter adjacent the open end thereof and is pivotally movable to close and open the open end. The shutter member extends across the optic axis of the connector/adapter assembly when the shutter member is closed. The shutter member is pivotable away from the optic axis to its open condition upon engagement by the inserted fiber optic connector.
One of the problems with opening protective shutters by engagement with the inserted end of the fiber optic connector, is that the ferrule and/or the end of the optical fiber terminated by the ferrule can be damaged by engaging and opening the shutter. For instance, the ferrule and/or fiber end of the connector may be highly polished. If the ferrule end is jammed against the shutter to move the shutter to its open position, the ferrule and/or fiber end can become contaminated, scratched or even broken. The present invention is directed to solving this problem in a fiber optic receptacle having a shutter automatically openable by engagement with an inserted connector.